Passive Device Files Screen

Passive Devices are simple passive components such as resistors, resistor packs and connectors. XJTAG represents these files using Passive Device Descriptor (*.pdd) files.

Passive Device Files List

The list of device files shows all passive device files currently associated with the project, including files which have no devices currently associated with them. If a passive device file is associated with any devices, or if the file is originally from an XJEase library, then this information will appear in the respective columns of the list. Clicking on a file in the list will display the properties for that device.

New passive device files can be created, or existing files added to the project, by clicking on Add... at the top of the file list to launch a popup screen, or selected files can be removed from the project by clicking Remove.

N.B. Files can only be removed from the project if no devices are currently assigned to use the file.

Device File Properties

The displayed properties of a file can be edited. When a file is edited, you must click the Save button in order to actually save the file. The Discard button will discard the changes you have made and reload the file from disk.

Version and Description

This box displays the version number for XJTAG library files and provides the option to add a description of the devices described by this file.

Used By

This box displays the list of devices that the file is used by.

Connections

The Connection List shows the current list of connections in the file. The user can edit this list using the Add and Remove buttons at the bottom of this section. Pin numbers can be typed straight into the From and To columns and the dropdown menu in the Connection Type column can be used to choose the connection type:

• Connect - a simple connection (or low-value resistor)
• Pull - a pull-resistor
• Couple - a coupling capacitor
• Diff. Term - a differential termination resistor, as used for a high-speed differential signal. The resistor should be used to describe a termination placed directly between the differential signal nets, and is not suitable for termination to a reference voltage or single-ended termination (e.g. DDR memory devices).
• Bias Term - a referenced termination resistor. This should be used to describe a resistor placed between a net and a termination reference voltage net. This is often seen around DDR memory devices, and/or used with differential signals, where positive and negative parts of the signal will each be terminated to the same reference voltage.

When you have finished, click Save to save the device file.